This invention relates to thiophenopyrimidines which possess CRF receptor antagonistic properties, to pharmaceutical compositions containing these compounds as active ingredient, and the use thereof in the treatment of endocrine, psychiatric and neurologic conditions or illnesses, including stress-related disorders in general.
The first corticotropin-releasing factor (CRF) was isolated from ovine hypothalmi and identified as a 41-amino acid peptide (Vale et al., Science 213:1394-1397, 1981). Subsequently, sequences of human and rat CRF were isolated and determined to be identical, but different from ovine CRF in 7 of the 41 amino acid residues (Rivier et al., Proc. Natl. Acad. Sci. USA 80:4851, 1983; Shibahara et al., EMBO J. 2:775, 1983). CRF has been found to produce profound alterations in endocrine, nervous and immune system functions. CRF is believed to be the major physiological regulator of the basal and stress-release of adrenocorticotropic hormone (xe2x80x9cACTHxe2x80x9d), xcex2-endorphin, and other pro-opiomelanocortin (xe2x80x9cPOMCxe2x80x9d)-derived peptides from the anterior pituitary (Vale et al., Science 213:1394-1397, 1981). Briefly, CRF is believed to initiate its biological effects by binding to a plasma membrane receptor which has been found to be distributed throughout the brain (DeSouza et al., Science 221:1449-1451, 1984), pituitary (DeSouza et al., Methods Enzyinol. 124:560, 1986; Wynn et al., Biochein. Biophlys. Res. Comm. 110:602-608, 1983), adrenals (Udelsman et al., Nature 319:147-150, 1986) and spleen (Webster, E. L., and E. B. DeSouza, Endocrinology 122:609-617, 1988). The CRF receptor is coupled to a GTP-binding protein (Perin et al., Endocrinology 118: 1171-1179, 1986) which mediates CRF-stimulated increase in intracellular production of cAMP (Bilezikjian, L. M., and W. W. Vale, Endocrinology 113:657-662, 1983).
In addition to its role in stimulating the production of ACTH and POMC, CRF is also believed to coordinate many of the endocrine autonomic, and behavioral responses to stress, and may be involved in the pathophysiology of affective disorders. Moreover, CRF is believed to be a key intermediary in communication between the immune, central nervous, endocrine and cardiovascular systems (Crofford et al., J. Clin. Invest. 90:2555-2564, 1992; Sapolsky et al., Science 238:522-524, 1987; Tilders et al., Regul. Peptides 5:77-84, 1982). Overall, CRF appears to be one of the pivotal central nervous system neurotransmitters and plays a crucial role in integrating the body""s overall response to stress.
Administration of CRF directly to the brain elicits behavioral, physiological, and endocrine responses identical to those observed for an animal exposed to a stressful environment. For example, intracerebrovenricular injection of CRF results in behavioral activation (Sutton et al., Nature 297:331, 1982), persistent activation of the electroencephalogram (Ehlers et al., Brain Res. 218332, 1983), stimulation of the sympathoadrenomedullary pathway (Brown et al., Endocrinology 110:928, 1982), an increase of heart rate and blood pressure (Fisher et al., Endocrinology 110:2222, 1982), an increase in oxygen consumption (Brown et al., Life Sciences 30:207, 1982), alteration of gastrointestinal activity (Williams et al., Am. J. Physiol. 253:G582, 1987), suppression of food consumption (Levine et al., Neurophannacology 22:337, 1983), modification of sexual behavior (Sirinathsinghji et al., Nature 305:232, 1983), and immune function compromise (Irwin et al., Am. J. Physiol. 255:R744, 1988). Furthermore, clinical data suggest that CRF may be hypersecreted in the brain in depression, anxiety-related disorders, and anorexia nervosa. (DeSouza, Ann. Reports in Med. Chew. 25:215-223, 1990).
Accordingly, clinical data suggest that CRF receptor antagonists may represent novel antidepressant and/or anxiolytic drugs that may be useful in the treatment of the neuropsychiatric disorders manifesting hypersecretion of CRF. CRF receptor antagonists have been reported in for example, U.S. Pat. No. 5,063,245 disclosing substituted 4-thio-5-oxo-3-pyrazoline derivatives and Australian Patent No. AU-A-41399/93, disclosing substituted 2-aminothiazole derivatives. Also, WO-94/13676, WO-94/13677 and WO-95/33750 disclose pyrrolopyrimidines, pyrazolo[3,4-d]pyrimidines and substituted purines as CRF receptor antagonists. EP-0,452,002 discloses thienopyrimidines as pesticides.
Due to the physiological significance of CRF, the development of further biologically active small molecules having significant CRF receptor binding activity and which are capable of antagonizing the CRF receptor remains a desirable goal. Such CRF receptor antagonists would be useful in the treatment of endocrine, psychiatric and neurologic conditions or illnesses, including stress-related disorders in general.
This invention concerns compounds of formula 
including the stereoisomers and the pharmaceutically acceptable acid addition salt forms thereof, wherein
X is S, SO or SO2;
R1 is NR4R5 or OR5;
R2 is C1-6alkyl, C1-6alkyloxy or C1-6alkylthio;
R3 is hydrogen, C1-6alkyl, C1-6alkylsulfonyl, C1-6alkylsulfoxy or C1-6alkylthio;
R4 is hydrogen, C1-6alkyl, mono- or di(C3-6cycloalkyl)methyl, C3-6cycloalkyl, C3-6alkenyl, hydroxyC1-6alkyl, C1-6alkylcarbonyloxyC1-6alkyl or C1-6alkyloxyC1-6alkyl;
R5 is C1-8alkyl, mono- or di(C3-6cycloalkyl)methyl, Ar1CH2, C1-6alkyloxyC1-6alkyl, hydroxyC1-6alkyl, C3-6alkenyl, thienylmethyl, furanylmethyl, C1-6alkylthioC1-6alkyl, morpholinyl, mono- or di(C1-6alkyl)aminoC1-6alkyl, di(C1-6alkyl)amino, C1-6alkylcarbonylC1-6alkyl, C1-6alkyl substituted with imidazolyl; or a radical of formula -Alk-O-CO-Ar1;
or R4 and R5 taken together with the nitrogen atom to which they are attached may form a pyrrolidinyl, piperidinyl, homopiperidinyl or morpholinyl group, optionally substituted with C1-6alkyl or C1-6alkyloxyC1-6alkyl;
Ar is phenyl; phenyl substituted with 1, 2 or 3 substituents independently selected from halo, C1-6alkyl, trifluoromethyl, hydroxy, cyano, C1-6alkyloxy, benzyloxy, C1-6alkylthio, nitro, amino and mono- or di(C1-6alkyl)amino; pyridinyl; pyridinyl substituted with 1, 2 or 3 substituents independently selected from halo, C1-6alkyl, trifluoromethyl, hydroxy, cyano, C1-6alkyloxy, benzyloxy, C1-6alkylthio, nitro, amino, mono- or di(C1-6alkyl)amino and piperidinyl; and wherein said substituted phenyl may optionally be further substituted with one or more halogens;
Ar1 is phenyl; phenyl substituted with 1, 2 or 3 substituents each independently selected from halo, C1-6alkyl, C1-6alkyloxy, di(C1-6alkyl)aminoC1-6alkyl, trifluoromethyl and C1-6alkyl substituted with morpholinyl; or pyridinyl; and
Alk is C1-6alkanediyl.
As used in the foregoing definitions and hereinafter, halo is generic to fluoro, chloro, bromo and iodo; C1-6alkanediyl defines bivalent straight and branched chained saturated hydrocarbon radicals having from 1 to 6 carbon atoms, such as, for example, methylene, 1,2-ethanediyl, 1,3-propanediyl, 1,4-butanediyl, 1,5-pentanediyl, 1,6-hexanediyl and the branched isomers thereof; C1-2alkyl defines straight saturated hydrocarbon radicals having from 1 to 2 carbon atoms such as methyl and ethyl; C2-4alkyl defines straight and branched chain saturated hydrocarbon radicals having from 2 to 4 carbon atoms such as ethyl, propyl, butyl, 1-methylethyl and the like; C3-4alkyl defines straight and branched chain saturated hydrocarbon radicals having from 3 to 4 carbon atoms such as propyl, butyl, 1-methylethyl and the like; C1-6alkyl includes C1-2alkyl and C3-4alkyl radicals as defined hereinbefore and the higher homologs thereof having from 5 to 6 carbon atoms such as, pentyl, the pentyl isomers, hexyl and the hexyl isomers; C1-8alkyl includes C1-6alkyl and the higher homologues thereof having from 7 to 8 carbon atoms such as, for example, heptyl, octyl and the like; C3-6alkenyl defines straight and branched chain hydrocarbon radicals containing one double bond and having from 3 to 6 carbon atoms such as, for example, 2-propenyl, 3-butenyl, 2-pentenyl, 3-pentenyl, 3-methyl-2-butenyl, and the like; and where said C3-6alkenyl is linked to a nitrogen or oxygen, the carbon atom making the link preferably is saturated. C3-6cycloalkyl comprises cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl. HydroxyC1-6alkyl refers to C1-6alkyl substituted with a hydroxylgroup. Homopiperidinyl refers to a 7 membered saturated ring containing one nitrogen atom.
Depending on the nature of some of the substituents, the compounds of formula (I) may contain one or more asymmetric centers which may be designated with the generally used R and S nomenclature.
The compounds of the present invention contain basic nitrogen atoms and, as such, can be present as the free base or in the form of acid addition salts, both being part of this invention. Acid addition salts may be prepared by methods well known in the art, and may be formed from organic and inorganic acids. Suitable organic acids include maleic, fumaric, benzoic, ascorbic, succinic, methanesulfonic, acetic, oxalic, propionic, tartaric, salicylic, citric, gluconic, lactic, mandelic, cinnamic, aspartic, stearic, palmitic, glycolic, glutamic, and benzenesulfonic acids. Suitable inorganic acids include hydrochloric, hydrobromic, sulfuric, phosphoric, and nitric acids.
Particular groups of compounds within the invention are those compounds of formula (I) wherein one or more of the following restrictions apply:
a) R1 is NR4R5 wherein R4 is C1-6alkyl or C1-6alkyloxyC1-6alkyl, and R5 is C1-6a C3-6alkenyl, C3-6cycloalkylmethyl or hydloxyC1-6alkyl; in particular R4 is C2-4alkyl or methoxyC1-2alkyl, and R5 is C2-4alkyl, cyclopropylmethyl or hydroxyC2-4alkyl;
b) or, R1 is OR5 wherein R5 is C1-6alkyl; in particular C2-4alkyl;
c) R2 is C1-6alkyl, in particular C1-2alkyl;
d) R3 is hydrogen or C1-6alkyl, in particular hydrogen or C1-2alkyl;
e) Ar is a phenyl substituted with 1, 2 or 3 substituents each independently selected from C1-6alkyl, C1-6alkyloxy or halo and one of the further hydrogens on said substituted phenyl may be a halo; in particular Ar is phenyl substituted on the 4-, 2,4- or 2,4,6-positions each independently with halo, C1-2alkyl or C1-2alkyloxy; or Ar is a pyridinyl substituted with 1, 2 or 3 substituents each independently selected from di(C1-6alkyl)amino or C1-6alkyl; in particular Ar is pyridinyl substituted on the 2,4-, 2,6- or 2,4,6-positions each independently with di(C1-2alkyl)amino or C1-2alkyl.
Another particular group of compounds are those compounds of formula (I) wherein R1 is NR4R5 and R4 and R5 are taken together with the nitrogen atom to which they are attached to form a pyrrolidinyl, piperidinyl, homopiperidinyl or morpholinyl group; optionally substituted with C1-6alkyl or C1-6alkyloxyC1-6alkyl.
Preferred compounds are those compounds of formula (I) wherein R1 is NR4R5 wherein R4 is C3-4alkyl or C1-2alkyloxyC3-4alkyl, preferably propyl; and R5 is C3-4alkyl or cyclopropylmethyl, preferably propyl; or R1 is OR5 wherein R5 is C3-4alkyl; R2 is methyl; R3 is hydrogen or methyl; and Ar is substituted in the 2-, 4- and 6-positions with halo or C1-4alkyl and optionally further substituted with a 3-halo; more preferably Ar is 2,4,6-trimethyl-phenyl, 3-bromo-2,4,6-trimethylphenyl, 6-(dimethylamino)-4-methyl-pyridinyl or 2,4-dimethylpyridinyl.
More preferably Ar is 3-pyridinyl substituted in the 4- and/or 6-position with methyl or dimethylamino.
Most preferred are those compounds selected from
2-methyl-6-(N-propyl-N-cyclopropylamino)-8-(2,4,6-trimethylphenyl)-thiopheno[3,2-d]pyrimidine; or
2-methyl-6-(N,N-dipropylamino)-8-(2,4,6-trimethylphenyl)-thiopheno[3,2-d]pyrimidine; the stereoisomeric forms and the pharmaceutically acceptable acid addition salts thereof.
The compounds of the present invention can generally be prepared by alkylating a thiazolopyrimidine of formula (II) with an intermediate of formula (III). 
In intermediate (II), W is an appropriate leaving group such as halo, e.g. chloro, bromo, or a sulfonyloxy group, e.g. a mesyloxy or a tosyloxy group. The above reaction is typically conducted in a suitable solvent, e.g. an aprotic solvent such as DMF or acetonitrile, an ether, e.g. tetrahydrofuran, preferably at an elevated temperature and, when intermediates of formula (III) are volatile amines, in a sealed reaction vial.
Also, compounds of formula (I) wherein R1 is OR5, said compounds being represented by formula (I-a), may be prepared by O-alkylating an intermediate of formula (IX) with an intermediate of formula (X), wherein W is as defined above. Said reaction can be performed in a reaction-inert solvent such as, for example, N,N-dimethylformamide, and in the presence of a suitable base such as, for example, sodium hydride, preferably at a temperature ranging between room temperature and reflux temperature. 
The compounds of formula (I) wherein R1 is NR4R5, represented by formula (I-c), can be prepared from either compounds of formula (XI) or (XII) by suitable N-alkylation reactions as depicted herebelow, wherein W is as previously defined. These N-alkylations are conducted in a reaction-inert solvent such as, for example, an ether e.g. tetrahydofuran and preferably in the presence of a strong base, e.g. NaH. 
In certain instances, this reaction can give rise to side products wherein R2 is alkylated by (R4 or R5)xe2x80x94W, in particular where R2 is methyl and R4 or R5 is lower alkyl.
As outlined below, compounds of formula (I) may be converted into each other following art-known transformation procedures.
For instance, compounds of formula (I) wherein X is S can be converted into compounds of formula (I) wherein X is SO or SO2 by an oxidation reaction, e.g. treatment with a peroxide such as 3-chloroperbenzoic acid in a reaction-inert solvent, e.g. dichloromethane. By controlling the amount of oxidant and other reaction parameters, either compounds of formula (I) wherein X is SO or X is SO2 can be obtained, or a mixture of both, which subsequently can be separated by conventional methods, e.g. column chromatography. Also, the compounds of formula (I) wherein R3 is C1-6alkylthio can be converted into compounds of formula (I) wherein R3 is C1-6alkylsulfonyl or C1-6alkylsulfoxy by an oxidation reaction similar as above described. By controlling the amount of oxidant and other reaction parameters, and by separating the end products, the various oxidated products can be separately obtained.
Further, the Ar group of compounds of formula (I) can be halogenated using a halogenating agent such as, e.g. chlorine or bromine, in a suitable solvent, e.g. acetic acid, and optionally the reaction may be performed at a temperature ranging between room temperature and the reflux temperature of the reaction mixture.
Stereoisomers may be prepared by separation of the end products of formula (I) following art-known procedures, e.g. by treatment with an optically active acid and separating the thus-formed diastereoisomeric salts by selective crystallization or column chromatography. Or, stereoisomers may be prepared by using stereoisomeric starting materials in any of the above reaction schemes or in the preparation of intermediates described hereinafter.
Intermediates of formula (II) wherein X is S, said intermediates being represented by compounds of formula (II-a), can be prepared as outlined herebelow. Intermediates of formula (VI) are prepared by treating intermediates of formula (V) with an ester of formula (V) in a reaction-inert solvent such as an alcohol, e.g. ethanol, preferably in the presence of a strong base such as, e.g. sodium ethoxide or sodium hydride. The intermediates (VI) are reacted with methaneshilphonyl chloride and subsequently with 2-(acetylthio)-acetonitrile, yielding aminothiophene derivatives of formula (VII). These are converted into intermediates (VIII) using conventional acylation methods such as, e.g. the use of an acid anhydride (R2CO)2O. Intermediates of formula (VIR) are cyclized to intermediates (IIxe2x80x2-b), in which the hydroxy group is converted into leaving group W, e.g. by treating intermediate (IIxe2x80x2-b) with methanesulfonyloxy chloride or a halogenating reagent such as, e.g. POCl3, thus yielding intermediates (II-a). 
Intermediates of formula (XI) are prepared by treating intermediates of formula (II) with ammonia.
In an embodiment, this invention also provides for compounds of formula (IIxe2x80x2-a), defined as compounds of formula (II-a) wherein Wxe2x80x2 represents hydroxy, halo, mesyloxy or tosyloxy. 
Said intermediates of formula (IIxe2x80x2-a) may be prepared according to procedures used to prepare intermediates of formula (II-a), thereby thereby yielding compounds of formula (IIxe2x80x2-b), defined as compounds of formula (IIxe2x80x2-a) wherein Wxe2x80x2 is hydroxy; and optionally converting compounds of formula (IIxe2x80x2-b) into compounds of formula (II-a), defined as compounds of formula (IIxe2x80x2-a) wherein Wxe2x80x2 is other than hydroxy.
The effectiveness of a compound as a CRF receptor antagonist may be determined by various assay methods. Suitable CRF antagonists of this invention are capable of inhibiting the specific binding of CRF to its receptor and antagonizing activities associated with CRF. A compound of structure (I) may be assessed for activity as a CRF antagonist by one or more generally accepted assays for this purpose, including (but not limited to) the assays disclosed by DeSouza et al. (J. Neuroscience 7:88, 1987) and Battaglia et al. (Synapse 1:572, 1987). As mentioned above, suitable CRF antagonists include compounds which demonstrate CRF receptor affinity. CRF receptor affinity may be determined by binding studies that measure the ability of a compound to inhibit the binding of a radiolabeled CRF (e.g. [125I]tyrosine CFR) to receptor (e.g., receptors prepared from rat cerebral cortex membranes). The radioligand binding assay described by DeSouza et al. (supra, 1987) provides an assay for determining a compound""s affinity for the CRF receptor. Such activity is typically calculated from the IC50 as the concentration of a compound necessary to displace 50% of the radiolabeled ligand from the receptor, and is reported as a xe2x80x9cKixe2x80x9d value calculated by the following equation:       K    i    =            IC      50              1      +              L        /                  K          D                    
where L=radioligand and KD=affinity of radioligand for receptor (Cheng and Prusoff, Biochem. Phannacol. 22:3099, 1973).
In addition to inhibiting CRF receptor binding, a compound""s CRF receptor antagonist activity may be established by the ability of the compound to antagonize an activity associated with CRF. For example, CRF is known to stimulate various biochemical processes, including adenylate cyclase activity. Therefore, compounds may be evaluated as CRF antagonists by their ability to antagonize CRF-stimulated adenylate cyclase activity by, for example, measuring cAMP levels. The CRF-stimulated adenylate cyclase activity assay described by Battaglia et al. (supra, 1987) provides an assay for determining a compound""s ability to antagonize CRF activity. Accordingly, CRF receptor antagonist activity may be determined by assay techniques which generally include an initial binding assay (such as disclosed by DeSouza (supra, 1987)) followed by a cAMP screening protocol (such as disclosed by Battaglia (supra, 1987)).
With reference to CRF receptor binding affinities, CRF receptor antagonists of this invention have a Ki of less than 10 xcexcM. In a preferred embodiment of this invention, a CRF receptor antagonist has a Ki of less than 1 xcexcM, and more preferably less than 0.25 xcexcM (i.e., 250 nM).
The CRF receptor antagonists of the present invention demonstrate activity at the CRF receptor site, and may be used as therapeutic agents for the treatment of a wide range of disorders or illnesses including endocrine, psychiatric, and neurologic disorders or illnesses. More specifically, the CRF receptor antagonists of the present invention may be useful in treating physiological conditions or disorders arising from the hypersecretion of CRF. Because CRF is believed to be a pivotal neurotransmitter that activates and coordinates the endocrine, behavioral and automatic responses to stress, the CRF receptor antagonists of the present invention can be used to treat neuropsychiatric disorders. Neuropsychiatric disorders which may be treatable by the CRF receptor antagonists of this invention include affective disorders such as depression; anxiety-related disorders such as generalized anxiety disorder, panic disorder, obsessive-compulsive disorder, abnormal aggression, cardiovascular abnormalities such as unstable angina and reactive hypertension; and feeding disorders such as anorexia nervosa, bulimia, and irritable bowel syndrome. CRF antagonists may also be useful in treating stress-induced immune suppression associated with various diseases states, as well as stroke. Other uses of the CRF antagonists of this invention include treatment of inflammatory conditions (such as rheumatoid arthritis, uveitis, asthma, inflammatory bowel disease and G.I. motility), Cushing""s disease, infantile spasms, epilepsy and other seizures in both infants and adults, and various substance abuse and withdrawal (including alcoholism).
In another embodiment of the invention, pharmaceutical compositions containing one or more CRF receptor antagonists are disclosed. For the purposes of administration, the compounds of the present invention may be formulated as pharmaceutical compositions. Pharmaceutical compositions of the present invention comprise a CRF receptor antagonist of the present invention (i.e., a compound of structure (I)) and a pharmaceutically acceptable carrier and/or diluent. The CRF receptor antagonist is present in the composition in an amount which is effective to treat a particular disorder, that is, in an amount sufficient to achieve CRF receptor antagonist activity, and preferably with acceptable toxicity to the patient. Preferably, the pharmaceutical compositions of the present invention may include a CRF receptor antagonist in an amount from 0.1 mg to 250 mg per dosage depending upon the route of administration, and more preferably from 1 mg to 60 mg. Appropriate concentrations and dosages can be readily determined by one skilled in the art.
Pharmaceutically acceptable carrier and/or diluents are familiar to those skilled in the art. For compositions formulated as liquid solutions, acceptable carriers and/or diluents include saline and sterile water, and may optionally include antioxidants, buffers, bacteriostats and other common additives. The compositions can also be formulated as pills, capsules, granules, or tablets which contain, in addition to a CRF receptor antagonist, diluents, dispersing and surface active agents, binders, and lubricants. One skilled in this art may further formulate the CRF receptor antagonist in an appropriate manner, and in accordance with accepted practices, such as those disclosed in Reinington""s Phannaceittical Sciences, Gennaro, Ed., Mack Publishing Co., Easton, USA, 1990.
In another embodiment, the present invention provides a method for treating a variety of disorders or illnesses, including endocrine, psychiatric and neurologic disorders or illnesses. Such methods include administering of a compound of the present invention to a warm-blooded animal in an amount sufficient to treat the disorder or illness. Such methods include systemic administration of a CRF receptor antagonist of this invention, preferably in the form of a pharmaceutical composition. As used herein, systemic administration includes oral and parenteral methods of administration. For oral administration, suitable pharmaceutical compositions of CRF receptor antagonists include powders, granules, pills, tablets, and capsules as well as liquids, syrups, suspensions, and emulsions. These compositions may also include flavorants, preservatives, suspending, thickening and emulsifying agents, and other pharmaceutically acceptable additives. For parental administration, the compounds of the present invention can be prepared in aqueous injection solutions which may contain, in addition to the CRF receptor antagonist, buffers, antioxidants, bacteriostats, and other additives commonly employed in such solutions.
As mentioned above, administration of a compound of the present invention can be used to treat a wide variety of disorders or illnesses. In particular, the compounds of the present invention may be administered to a warm-blooded animal for the treatment of depression, anxiety disorder, panic disorder, obsessive-compulsive disorder, abnormal aggression, unstable angina, reactive hypertension, anorexia nervosa, bulimia, irritable bowel syndrome, stress-induced immune suppression, stroke, inflammation, Cushing""s disease, infantile spasms, epilepsy, and substance abuse or withdrawal.
Hence, the use of a compound of formula (I) as a medicine is provided